[time-nuts] LPFRS analog C-field adjust

[Azelio Boriani]

Today, trying to figure out how to get control of the C-field directly, I
found that the analog fine tune input is already connected directly to the
C-field coil summing point via a 12K resistor, an op-amp (a buffer) and a
560 resistor. The other contributor is the DAC8800 pin 17 (Voutg) via a
12K/op-amp/2K7). So the EFC is not A/D converted and then D/A converted
back to analog, at least not in the LPFRS-01 I have (made in 2003).